Which heat transfer mode is active when a metal spoon placed in hot soup becomes warm along its length?

Which heat transfer mode is active when a metal spoon placed in hot soup becomes warm along its length?

• A. Reflection
• B. Conduction
• C. Convection
• D. Radiation

Answer: (B)

Heat transfer through a solid in contact with a hotter object occurs by conduction. When the metal spoon sits in hot soup, energy moves from the soup into the spoon at the point of contact. In a metal, free electrons and closely packed atoms transfer this energy quickly along the length of the spoon, so the entire spoon warms up, not just the part touching the soup. This shows conduction in action. Convection would require moving fluids to transfer heat, and radiation would heat the spoon without contact, which isn’t what’s mainly happening here.

Heat transfer through a solid in contact with a hotter object occurs by conduction. When the metal spoon sits in hot soup, energy moves from the soup into the spoon at the point of contact. In a metal, free electrons and closely packed atoms transfer this energy quickly along the length of the spoon, so the entire spoon warms up, not just the part touching the soup. This shows conduction in action. Convection would require moving fluids to transfer heat, and radiation would heat the spoon without contact, which isn’t what’s mainly happening here.